LORING, Terry A. When matrices commute. Mathematica Scandinavica, Berkeley, CA, United States, v. 82, n. 2, p. 305–319, 1998. DOI: 10.7146/math.scand.a-13839. Disponível em: https://journals.msp.org/mscand/article/view/989. Acesso em: 25 jul. 2026.